Perpetual Futures Explained: Leverage Trading Without an Expiry Date

Traditional futures contracts settle on a fixed date — you agree today on a price for an asset you'll buy or sell next month, and when that month arrives, the contract closes out. Perpetual futures, or "perps," strip away the expiry date entirely. You can hold a leveraged long or short position indefinitely, as long as your margin holds up. That single design choice is why perps became the dominant way to trade crypto with leverage, and why understanding the mechanism that holds them together matters before you open one.

Without an expiry date, a perpetual contract has no natural moment to force its price back in line with the actual spot price of the asset. A dated futures contract solves this through settlement — buyers and sellers know the contract converges to spot on a specific day, so arbitrage keeps the price honest as that date approaches. Perps needed a different mechanism, since there's no settlement day to anchor to. The answer, first popularized by BitMEX in 2016, is the funding rate.

Every few hours (commonly every 8 hours, though intervals vary by exchange), traders holding one side of the contract pay traders holding the other side, based on the gap between the perpetual contract's price and the underlying spot price. If perp price is trading above spot — meaning more traders want to be long than short — longs pay shorts. If perp price is below spot, shorts pay longs. This payment is the funding rate, and it's the entire mechanism holding a perpetual contract's price close to the real market price without ever settling.

The rate itself is just a cost of holding a position, paid directly between traders (the exchange usually isn't the counterparty to funding payments — it just facilitates the transfer). When funding is strongly positive, it means the market is heavily skewed long and leverage-hungry longs are effectively subsidizing shorts to keep the trade balanced. Extreme funding rates are also a widely-watched sentiment signal: a spike in positive funding across major perp exchanges is often read as a sign a market is overheated and due for a squeeze in the other direction.

Perps are almost always traded with leverage — you post a fraction of a position's notional value as margin, and the exchange (or protocol, for on-chain perps) lets you control a much larger position. 10x leverage means a 10% move against you wipes out your margin; 50x leverage means a 2% move does the same. When your margin balance falls below the maintenance threshold, the position gets automatically liquidated, and on high-leverage positions that can happen from ordinary intraday volatility, not just a major market move.

This is the mechanism most new perp traders underestimate. It's not enough to be directionally correct — you also have to survive the noise between now and being correct. A trader who was right about ETH's direction over the following week can still get liquidated on hour four if their leverage was too high for the position to absorb a normal pullback.

Centralized exchanges (Binance, Bybit, OKX and similar) run the largest perp markets by volume, matching orders off-chain with an internal order book and using an insurance fund to absorb losses when liquidations can't be filled at the expected price. On-chain perp protocols (dYdX, Hyperliquid, GMX and others) replicate the same funding-rate mechanism but settle trades and hold collateral on a blockchain, trading some speed and capital efficiency for self-custody and transparent, auditable liquidation logic. The core funding-rate design is nearly identical across both — what differs is who holds your collateral and how disputes get resolved.

Before opening a perpetual position, check the current funding rate, not just the price chart — a position with the right direction can still bleed money to funding payments if you're on the crowded side of the trade. Size leverage around how far the asset realistically moves against you on a bad day, not around the return you're hoping for on a good one. And remember that liquidation is calculated on mark price, not the price you saw when you clicked buy, so give yourself more room than the leverage slider technically allows.